1. Field of the Invention
The present invention relates to a punch secured to a press brake and more particularly, to a device for securing the vertical position of a punch relative to a press brake.
2. Background of the Prior Art
A punch-press brake combination is routinely utilized to form strips or sheets of metal into a myriad of configurations. Referring to FIG. 1, a side elevation view of a typical prior art punch-press brake installation is depicted. The press brake 4 includes a channel member 5 bolted to a base member 6 with a punch 7 positioned between a holding wall 8 of the channel member 5 and a base wall 9 of the base member 6. The punch 7 is vertically held in place by a plurality of tightened horizontal clamping screws that horizontally xe2x80x9csqueezexe2x80x9d the punch between the holding and base walls 8 and 9 of the press brake 4.
The problem with this securing method is that the punch 7 is often comprised of multiple sections that have a tendency to loosen and slip downward causing an unacceptable deforming of the metal strips or sheets. Some press brakes 4 have press beds that can exceed twelve feet in length thereby requiring multiple punches or punch segments 7 of a predetermined form to be longitudinally aligned to configure a metal workpiece covering the length of the press bed. These punches 7 often have lengths that dispose a punch 7 in the press brake such that the ends of the punch are positioned from the bolts joining the channel member 5 to the base member 6, a distance that allows a punch end to slip downward and become misaligned during assembly of the punch-brake press combination. Some relatively small punch segments have longitudinal dimensions measuring less than the distance separating adjacent bolts making these small segments unusable.
Another problem with the prior method of securing the punch 7 to the press brake 4, is that safety is comprised when an operator places their hands beneath a punch 7 that might slip from the press brake 4. Government agencies (OSHA) and insurance companies have addressed the safety issue by requiring a safety xe2x80x9ctonguexe2x80x9d to be machined into the upper portion of a punch 7.
A need exists for a device that quickly, economically and safely secures a predetermined punch 7 to a press brake 4. Further, the device must be readily secured to a press brake 4 such that the vertical position and the job performance of the punch 7 is maintained without any modifications to the press brake 4.
It is an object of the present invention to overcome many of the disadvantages associated with a punch being secured to a press brake.
A principle object of the present invention is to provide a device that secures and vertically maintains a punch within a press brake. A feature of the device is an extension portion or xe2x80x9cpunch tonguexe2x80x9d that protrudes beyond a vertical wall of the punch. An advantage of the device is that the extension portion is a relatively xe2x80x9csimple wayxe2x80x9d to secure the punch to the press brake.
Another object of the present invention is to provide a device that secures a punch to a press brake without modifying the press brake. A feature of the device is an extension portion dimensioned to insert in relatively small existing spaces in a press brake. An advantage of the device is that no modification costs for the press brake are required.
Yet another object of the present invention is to provide a device that requires a small quantity of components to secure the device to the punch. A feature of the device is a substantially cylindrically configured first member that snugly inserts into a correspondingly configured aperture in a top portion of the punch. An advantage of the device is that installation costs are minimized.
Still another object of the present invention is to provide a device that includes a solid xe2x80x9cunibodyxe2x80x9d construction. A feature of the device is a second member integrally joined to the first member. An advantage of the device is that no components are present that can xe2x80x9cwork freexe2x80x9d and allow the punch to move vertically downward.
Another object of the present invention is to provide a device that has a first member vertically secured in an aperture in a top portion of the punch and a second member that engages a top wall of the punch. A feature of the device is slot formed in a top wall of the punch due to the relatively close proximity of an aperture to the top wall of the punch. An advantage of the device is that the first member can be vertically secured to the punch without requiring added components. Another advantage of the device is that a protruding portion of the first member can be disposed in the slot and be ultimately joined to the second member such that a bottom wall of the second member engages a top wall of the punch thereby positioning the second portion to engage the press brake.
Another object of the present invention is to provide a device that allows xe2x80x9cscrapxe2x80x9d punches to be reused in a relatively large press brake. A feature of the device is it""s relatively small size. Another feature of the device is that it is relatively inexpensive to fabricate. An advantage of the device is that multiple device can be installed along the top portion of a punch as required to insure that the punch is vertically secured in a press brake.
Another object of the present invention is to provide a device that limits horizontal movement when a first member is inserted into an aperture in a top portion of a punch. A feature of the device is a lip portion that ultimately engages a top portion of a vertical side wall of a punch. An advantage of the device is that a bottom wall of the lip portion is correctly disposed to engage a cooperating portion of a press brake to vertically secure the device and the punch.
Another object of the present invention is to provide a device that maintains the horizontal position of a first member upon being inserted into an aperture in the top portion of the punch. A feature of the device is a countersunk set screw centrally disposed through the joined first and second members such that a rounded end of the set screw protrudes past a bottom portion of the first member to forcibly engage a wall portion of the aperture thereby frictionally joining top walls of the first member with cooperating wall portions of the aperture. An advantage of the device is that the first member cannot slip from the aperture in the punch when the punch is being secured to corresponding portions of the press brake during the machine xe2x80x9cset-upxe2x80x9d process.
Briefly, the invention provides a device for securing a punch to a press brake comprising a first member; a second member integrally joined to said first member; means for removably securing said first member to the punch; means for removably securing said second member to a cooperating portion of the press brake; and means for maintaining a predetermined position of said integrally joined first and second members relative to the punch.